Black Sand Cable Power Cords How Good?

How good are the Black Sand Cable power cords? I want to upgrade my stock power cords on my integrated amp and cd player. I have been reading some very positive comments on these cords. I would appreciate any comments from current and previous owners. Budget around three to five hundred for each cord. Thanks.

System:
Plinius 9200
CDP:Naim CD5I-2
DNM Speaker & IC cables
Speakers:Dynaudio Focus 140's on sound anchor 3 post stands